Search results for "VIROLOGY"
showing 10 items of 2354 documents
Antibody trapping: A novel mechanism of parasite immune evasion by the trematode Echinostoma caproni
2017
Background Helminth infections are among the most prevalent neglected tropical diseases, causing an enormous impact in global health and the socioeconomic growth of developing countries. In this context, the study of helminth biology, with emphasis on host-parasite interactions, appears as a promising approach for developing new tools to prevent and control these infections. Methods/Principal findings The role that antibody responses have on helminth infections is still not well understood. To go in depth into this issue, work on the intestinal helminth Echinostoma caproni (Trematoda: Echinostomatidae) has been undertaken. Adult parasites were recovered from infected mice and cultured in vi…
Lamivudine/Adefovir Treatment Increases the Rate of Spontaneous Mutation of Hepatitis B Virus in Patients.
2016
The high levels of genetic diversity shown by hepatitis B virus (HBV) are commonly attributed to the low fidelity of its polymerase. However, the rate of spontaneous mutation of human HBV in vivo is currently unknown. Here, based on the evolutionary principle that the population frequency of lethal mutations equals the rate at which they are produced, we have estimated the mutation rate of HBV in vivo by scoring premature stop codons in 621 publicly available, full-length, molecular clone sequences derived from patients. This yielded an estimate of 8.7 × 10-5 spontaneous mutations per nucleotide per cell infection in untreated patients, which should be taken as an upper limit estimate becau…
Case-based surveillance of measles in Sicily during 2012-2017: The changing molecular epidemiology and implications for vaccine strategies.
2018
Following the indication of the World Health Organization, a national plan for the elimination of measles was approved in Italy and this included the improvement of the molecular surveil- lance of measles viruses and the interruption of indigenous transmission of the disease. Nevertheless, large outbreaks continue to occur in almost all regions of the country, includ- ing Sicily. Here we describe the epidemiology and molecular dynamics of measles viruses as a result of the measles surveillance activity carried out by the “Reference Laboratory for Measles and Rubella” in Sicily over a 5-year period. Biological samples of 259 suspected measles cases were tested for viral RNA detection and a t…
Clinical severity and molecular characteristics of circulating and emerging rotaviruses in young children attending hospital emergency departments in…
2016
International audience; Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in young children worldwide. A prospective surveillance network has been set up to investigate the virological and clinical features of RVA infections and to detect the emergence of potentially epidemic strains in France. From 2009 to 2014, RVA-positive stool samples were collected from 4800 children <5 years old attending the paediatric emergency units of 16 large hospitals. Rotaviruses were then genotyped by RT-PCR with regard to their outer capsid proteins VP4 and VP7. Genotyping of 4708 RVA showed that G1P[8] strains (62.2%) were predominant. The incidence of G9P[8] (11.5%), G3P[8] (10.4%) and …
Cryptosporidiosis Outbreak in Immunocompetent Children from a Remote Area of French Guiana: CRYPTOSPORIDIOSIS OUTBREAK IN AMAZONIAN CHILDREN
2018
International audience; In September 2014, an increase in the number of Cryptosporidium spp. gastrointestinal tract infections was reported over a 6-month period among children living in a remote area along the Maroni River in French Guiana. Children presented gastroenteritis symptoms with Cryptosporidium-positive stools. Questionnaires were administered and stool examinations were controlled 3 months after the onset of symptoms. Data collection included demographics, food consumption, river behavior, symptoms, and outcome. Stool specimens were tested using microscopy and polymerase chain reaction. Samples from the water systems were examined for turbidity and culture for bacteria. Data fro…
Histo-blood group antigens in children with symptomatic rotavirus infection
2019
Group A rotaviruses are a major cause of acute gastroenteritis in children. The diversity and unequal geographical prevalence of rotavirus genotypes have been linked to histo-blood group antigens (HBGAs) in different human populations. In order to evaluate the role of HBGAs in rotavirus infections in our population, secretor status (FUT2+), ABO blood group, and Lewis antigens were determined in children attended for rotavirus gastroenteritis in Valencia, Spain. During three consecutive years (2013&ndash
Circulation and diagnostics of Puumala virus in Norway: nephropatia epidemica incidence and rodent population dynamics.
2017
Hantaviruses pose a public health concern worldwide causing haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Puumala virus (PUUV) is the most prevalent hantavirus in Central and Northern Europe, and causes a mild form of HFRS, also known as nephropathia epidemica (NE). In nature, the main host of PUUV is the bank vole (Myodes glareolus), and transmission to humans occurs through inhalation of aerosols from rodent excreta. Nephropathia epidemica is particularly prevalent in Nordic countries, however, few studies of PUUV have been performed in Norway. The aim of this study was to analyse the dynamics of PUUV in Norway and compare with bank vole population…
Performance evaluation of gastrointestinal viral ELIte panel multiplex RT-PCR assay for the diagnosis of rotavirus, adenovirus and astrovirus infecti…
2019
Rotavirus, adenovirus, norovirus and astrovirus are considered to be among the major causes of sporadic cases and outbreaks of acute gastroenteritis globally. Rapid and accurate identification of enteric viruses is still a challenge for the clinical laboratory. Recently, several molecular platforms for the detection of viral enteric pathogens have become available. In this study, the diagnostic accuracy of InGenius Gastrointestinal Viral (GV) Elite Panel, a newly developed one-step multiplex real-time RT-PCR assay simultaneously detecting rotavirus, adenovirus and astrovirus, was evaluated retrospectively analyzing an archival collection of 128 stool samples of children hospitalized with ac…
Hepatitis E virus-induced primary cutaneous CD30(+) T cell lymphoproliferative disorder.
2017
International audience; BACKGROUND & AIM:Several types of unexplained extra-hepatic manifestations, including haematological disorders, have been reported in the context of hepatitis E virus (HEV) infection. However, the underlying mechanism(s) of these manifestations are unknown. We provide evidence that HEV has an extra-hepatic endothelial tropism that can engage cutaneous T cells towards clonality.METHODS:A patient with a CD30(+) cutaneous T cell lymphoproliferative disorder (T-LPD) and biopsy-proven chronic HEV infection received three rounds of oral ribavirin treatment, administered either without or with interferon, and eventually achieved a sustained virologic response (SVR). Patholo…
Evaluation of HIV transmission clusters among natives and foreigners living in Italy
2020
We aimed at evaluating the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and migrants living in Italy, diagnosed between 1998 and 2018. Phylogenetic analyses were performed on HIV-1 polymerase (pol) sequences to characterise subtypes and identify MTCs, divided into small (SMTCs, 2&ndash